No abriremos la ventana a menos que haga calor.

We will not open the window unless it is hot.

Breakdown of No abriremos la ventana a menos que haga calor.

• nosotros: we
• abrir: to open
• la ventana: the window
• no: not
• a menos que: unless
• hacer calor: to be hot

Questions & Answers about No abriremos la ventana a menos que haga calor.

Why does the sentence use haga calor and not hace calor?

Because a menos que (unless) requires the subjunctive. It introduces a hypothetical or not-yet-realized condition, so you use subjunctive: a menos que + subjunctive. Here the weather being hot is uncertain, so it’s haga (present subjunctive of hacer), not hace (present indicative).

What verb form is haga exactly, and how is it conjugated?

Haga is the present subjunctive of hacer (3rd person singular). In Latin American Spanish you’ll commonly need these forms:

• yo: haga
• tú: hagas
• él/ella/usted: haga
• nosotros: hagamos
• ustedes/ellos: hagan

Why do we say hace calor for the weather? Can I say está caliente or hay calor?

• For weather, Spanish idiomatically uses hacer: hace calor / hace frío.
• Está caliente is for objects/liquids (The soup is hot). For people, estoy caliente is usually sexual in Latin America—avoid it if you mean you feel warm; say tengo calor.
• Hay calor is not the normal way to talk about weather heat; use hace calor.

Could I write the sentence starting with the condition?

Yes: A menos que haga calor, no abriremos la ventana. When the subordinate clause comes first, use a comma after it. If it comes after the main clause (as in the original), no comma is needed.

Is No vamos a abrir la ventana more natural than No abriremos la ventana?

Both are fine:

• No vamos a abrir… (ir a + infinitive) is very common in conversation.
• No abriremos… (simple future) can sound a bit more formal, planned, or resolute. You can also use the present for near-future plans if context is clear: No abrimos la ventana…

Is there a way to express this with si (if)? Are they equivalent?

Closest equivalent: Solo abriremos la ventana si hace calor. Be careful with: Si no hace calor, no abriremos la ventana. That’s logically related but weaker: it says you won’t open it if it’s not hot, but it doesn’t promise you will open it if it is hot. A menos que and solo si make the condition exclusive.

Is a menos de que acceptable?

You’ll hear a menos de que in parts of Latin America, but most grammars and style guides prefer a menos que. In careful writing, stick with a menos que. In any case, it still takes the subjunctive.

How would I say this about the past or a hypothetical?

• Past habit: No abríamos la ventana a menos que hiciera calor.
• One specific past situation: No abrimos la ventana a menos que hiciera calor.
• Hypothetical (wouldn’t unless): No abriríamos la ventana a menos que hiciera calor. Note the imperfect subjunctive hiciera after a menos que in past or hypothetical contexts.

Why is it la ventana? Can I omit the article?

Spanish normally uses a definite article with concrete, countable nouns: la ventana. Omitting it (abriremos ventana) sounds ungrammatical in ordinary speech.

Can I replace la ventana with a pronoun?

Yes: No la abriremos a menos que haga calor. With ir a + infinitive, both are correct:

• No la vamos a abrir…
• No vamos a abrirla… With the simple future, the pronoun goes before the verb: not abriremosla, but la abriremos.

Do I need to say nosotros?

No. Spanish normally drops subject pronouns because the verb ending (-emos in abriremos) already shows the subject. Use nosotros only for emphasis or contrast: Nosotros no abriremos…

How do you pronounce haga and hacer?

• h is silent in Spanish.
• haga = [AH-gah], with a hard g as in “go.”
• hacer = [ah-SER] (in most of Latin America the c before e sounds like s).

Why is que not accented (qué) in a menos que?

Because it’s a conjunction here. Qué with an accent is interrogative/exclamative. Conjunction que is written without an accent: a menos que.

If I want to say “unless it gets hot,” do I need a different verb?

No change is needed. Spanish often uses the present subjunctive for future reference: a menos que haga calor naturally covers “unless it gets hot.” If you want to be very explicit about a change, you could say a menos que suba la temperatura, but haga calor is standard.

Is a menos que no ever correct?

Avoid it. A menos que already conveys the negative logic of “unless,” so adding no flips the meaning: A menos que no llueva ≈ “unless it doesn’t rain” (i.e., if it rains). For your sentence, say a menos que haga calor, not a menos que no haga calor.

Are there synonyms for a menos que?

Yes:

• a no ser que: No abriremos la ventana a no ser que haga calor.
• salvo que: No abriremos la ventana salvo que haga calor. Also possible are excepto si / salvo si with the indicative: No abriremos la ventana excepto si hace calor.

Why is the verb weather-related and impersonal here?

Weather expressions are impersonal in Spanish. You say hace calor (it’s hot), and in the subjunctive that becomes haga calor. It’s always third-person singular because there’s no explicit subject.

Can I add detail like “outside” or “a lot”?

Yes:

• Intensity: …a menos que haga mucho calor.
• Location/context: …a menos que afuera haga calor. Both keep the subjunctive after a menos que.